NASA’s Hubble snaps rare photo of Uranus

NASA’s Hubble Space Telescope has spotted auroras on Uranus, according to a statement from the American Geophysical Union. The stunning photos of the auroras were captured on November 16, 2011 and November 29. On those dates, Hubble glimpsed faint circles on Uranus.

This is the first time the researchers have seen the auroras on Uranus with an Earth-based telescope. Scientists note that the auroras on Uranus lasted for a short period of time, whereas the ones on Earth can last for hours and turn the sky green and red.

“This planet was only investigated in detail once, during the Voyager flyby, dating from 1986. Since then, we’ve had no opportunities to get new observations of this very unusual magnetosphere,” noted Laurent Lamy, a researcher at the Paris Observatory, in a statement.

Voyager 2 crossed paths with Uranus on January 24, 1986. The spacecraft sent back detailed photos and other data on Uranus.

The photos are the first images of the auroras of the planet. Scientists hope that Hubble’s discovery will reveal previously unknown facts about Uranus’ magnetosphere.

“The magnetosphere of Uranus is very poorly known,” said Mr. Lamy.

On Earth, auroras come from the interaction between the solar wind and the planet’s magnetic field. Terrestrial auroras are typically found around high altitudes, however, it remains unclear what causes the auroras on Uranus. Researchers suspect that the unfamiliar appearance of the newly observed auroras is due to Uranus’ rotational weirdness and peculiar traits of its magnetic axis.

Uranus is the seventh planet from the Sun. The planet is unique in that its equator is nearly at right angles to its orbit. Scientists believe that a collision with another object may be to blame for Uranus’ strange tilt.

Auroras on Uranus are fainter than they are on Earth, the team of astronomers noted. The planet is more than 4 billion kilometers (2.5 billion miles) away from Earth and previous Earth-bound attempts to detect the faint auroras did not reveal any conclusive data. Astronomers last observed Uranian auroras 25 years ago when the Voyager 2 spacecraft passed the planet.

Researchers believe that the differences between the auroras observed on Uranus and the ones found on Earth can be explained by Uranus’ abnormal tilt. A better understanding of Uranus’ magnetosphere could help scientists better craft their theories of how Earth’s magnetosphere function, say researchers.

NASA’s Hubble Space Telescope blasted off into orbit on April 24, 1990. Over the years, Hubble has provided countless researchers the ability to study distant stars and massive black holes.

A study on the discovery of auroras on Uranus appeared in a recent issue of the Geophysical Research Letters.